Ceramic Application & Contouring Flashcards

When building up incisal edge translucency on an anterior crown, which ceramic layering technique best mimics natural enamel optical properties?

Answer: Layer thin increments of incisal/enamel ceramic over dentin build-up, allowing light transmission

Thin incremental layering of incisal/enamel ceramic over a dentin core recreates natural light diffusion and translucency characteristic of real enamel.

What is the primary purpose of the 'shoulder' or 'bevel' preparation when applying porcelain to a PFM crown?

Answer: To provide space for adequate ceramic thickness and esthetic margin

A shoulder or bevel margin provides sufficient space (typically ≥1.5 mm) for ceramic buildup that achieves both esthetics and strength at the margin.

When contouring buccal contours of a ceramic restoration, a dentist notices the emergence profile appears too flat. What adjustment best corrects this?

Answer: Add ceramic to the cervical third and re-fire

A flat emergence profile is corrected by adding ceramic mass at the cervical-to-mid-buccal area to create a natural convex contour before the final fire.

Which of the following describes 'overfiring' of feldspathic porcelain during the build-up stage?

Answer: Ceramic becomes too glossy and loses surface texture, and internal strength may be compromised

Overfiring causes excessive fluidity, collapsing surface texture and potentially altering crystal structure, resulting in a glassy, weakened restoration.

During ceramic contouring, which area of a posterior crown most commonly requires reduction to prevent premature occlusal contact?

Answer: Marginal ridges and cusp tips

Marginal ridges and cusp tips are the highest points in posterior occlusion and are most prone to ceramic over-build causing premature contacts.

What effect does repeated firing have on the shade of an alumina-reinforced ceramic restoration?

Answer: Color may lighten or shift due to changes in fluorescence and opacity with multiple heat cycles

Multiple firing cycles can alter internal pigments, fluorescence, and crystal content, causing unpredictable shade shifts that necessitate shade checks between firings.

When applying cervical ceramic to recreate a natural gingival emergence profile, the ceramist should build the cervical area:

Answer: Convex and tapering toward the margin, mimicking natural root emergence

Natural teeth emerge from the gingiva with a convex profile that tapers toward the cemento-enamel junction; ceramic should replicate this for healthy tissue response.